This invention pertains to a glaucoma treatment method, and more particularly to a method utilizing a laser to create a fluid drainage passage between the anterior chamber of an eye and the Canal of Schlemm and a device which assists a surgeon performing the treatment.
Glaucoma is a relatively common eye disease resulting from pressure build-up in the anterior chamber due to blocked or seriously impaired drainage of aqueous humor from this chamber.
Various techniques and medications which have been used in the past to alleviate symptoms of galucoma have proven often to be quite expensive and not entirely satisfactory, in that, among other things, recurrent treatment is necessary, and inconvenient.
A general object of the present invention is to provide a unique, relatively low-cost, effective method for treating a glaucoma condition.
More specifically, an object of the invention is to provide such a method which utilizes a pulse of light from a laser to create a fluid drainage passage (or more than one passage if need be) extending between the anterior chamber and the Canal of Schlemm, which passage effectively promotes the drainage of aqueous humor, and thus obviates damaging pressure build-up in the anterior chamber.
Another object of the invention is to provide a surgical device to assit a surgeon performing a treatment according to the invention.
Yet another object of the invention is to provide a method of the type generally mentioned which can be performed relatively simply on an outpatient basis, with long-term beneficial results.
According to one method of practicing the invention, blood normally draining from the Canal of Schlemm through the aqueous veins of Ascher is blocked by rim pressure applied externally to the periphery of the cornea--thus to engorge the Canal with blood. Such engorgement shifts the Canal's apparent color toward that of blood. With the Canal blood-engorged, and therefore readily recognizable, a laser beam pulse is directed, as through a conventional Goldman gonioscopic three-mirror lens, to create the desired drainage passage. One type of laser which has been found to be particularly effective is a laser utilizing a YAG (Yttrium-Aluminum-Garnet) crystal.
According to another method of practicing the invention, peferrably with blood engorgement of the Canal, a preliminary YAG laser beam pulse is directed toward the region where a final passage is desired, for the purpose of creating what is called herein a "passage-starting" crater in the trabecular meshwork which lies between the anterior chamber and the Canal of Schlemm. Thereafter, blood engorgement and laser impingement, as described according to the first method, are performed to complete the treatment procedure.
A vacuum-forming device, which receives a Goldman lens, may be used to facilitate blood engorgement.
As will be appreciated from the description which follows, treatment according to the method of the invention is accomplished cheaply, swiftly, and effectively.
Various other objects and advantages which are attained by the invention, will become more fully apparent as the description which now follows is read in conjunction with the accompanying drawings.